Strain relaxation in GaN grown on vicinal 4H-SiC(0001) substrates

The strain of GaN layers grown by Metal Organic Chemical Vapor Deposition (MOCVD) on three vicinal 4H-SiC substrates (0, 3.4 and 8 offcut from [0001] towards [11-20] axis) is investigated by X-ray Diffraction (XRD), Raman Scattering and Cathodoluminescence (CL). The strain relaxation mechanisms are analyzed for each miscut angle. At a microscopic scale, the GaN layer grown on on-axis substrate has a slight and homogeneous tensile in-plane stress due to a uniform distribution of threading dislocations over the whole surface. The GaN layers grown on miscut substrates presented cracks, separating areas which have a stronger tensile in-plane stress but a more elastic strain. The plastic relaxation mechanisms involved in these layers are attributed to the step flow growth on misoriented surfaces (dislocations and stacking faults) and to the macroscopical plastic release of additional thermoelastic stress upon cooling down (cracks)

Clinical trial of tailored activity and eating newsletters with older rural women.

BACKGROUND: Unhealthy diet and lack of physical activity increase rural midlife and older women\u27s risk of chronic diseases and premature death, and they are behind urban residents in meeting Healthy People 2010 objectives. OBJECTIVES: The objective of this study was to compare a tailored intervention based on the Health Promotion Model with a generic intervention to increase physical activity and healthy eating among rural women. METHODS: In a randomized-by-site, community-based, controlled, clinical trial, Wellness for Women, 225 women aged 50 to 69 years were recruited in two similar rural areas. Over 12 months, women received by mail either 18 generic newsletters or 18 newsletters computer tailored on Health Promotion Model behavior-specific cognitions (benefits, barriers, self-efficacy, and interpersonal support), activity, and eating. Outcomes at 6 and 12 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed by repeated-measures analysis of variance and chi-square tests (alpha \u3c .05). RESULTS: Both groups significantly increased stretching and strengthening exercise and fruit and vegetable servings and decreased percentage of calories from fat, whereas only the tailored group increased moderate or greater intensity activity and decreased percentage of calories from saturated fat from baseline to 6 months. Both groups increased stretching and strengthening exercise, whereas only the tailored group increased moderate or greater intensity activity and fruit and vegetable servings and decreased percentage of calories from fat from baseline to 12 months. Both groups had several changes in biomarkers over the study. A higher proportion of women receiving tailored newsletters met Healthy People 2010 criteria for moderate or greater intensity activity, fruit and vegetable servings, and percentage of calories from fat at 12 months. DISCUSSION: Mailed computer-tailored and generic print newsletters facilitated the adoption of change in both activity and eating over 6 months. Tailored newsletters were more efficacious in facilitating change over 12 months

Impact of Tryptophan Oxidation in Complementarity-Determining Regions of Two Monoclonal Antibodies on Structure-Function Characterized by Hydrogen-Deuterium Exchange Mass Spectrometry and Surface Plasmon Resonance

This work is licensed under a Creative Commons Attribution 4.0 International License.Purpose Tryptophan’s (Trp) unique hydrophobic and structural properties make it an important antigen binding motif when positioned in complementarity-determining regions (CDRs) of monoclonal antibodies (mAbs). Oxidation of Trp residues within the CDR can deleteriously impact antigen binding, particularly if the CDR conformation is altered. The goal of this study was to evaluate the conformational and functional impact of Trp oxidation for two mAb subtypes, which is essential in determining the structure-function relationship and establishing appropriate analytical control strategies during protein therapeutics development. Methods Selective Trp oxidation was induced by 2,2′-Azobis(2-amidinopropane) dihydrochloride (AAPH) treatment in the presence of free methionine (Met). The native and chemically oxidized mAbs were characterized by hydrogen-deuterium exchange mass spectrometry (HDX-MS) for conformational changes and surface plasmon resonance (SPR) for antigen-antibody binding. Results Treatment of mAbs with AAPH selectively oxidized solvent accessible Trp residues. Oxidation of Trp within or in proximity of CDRs increased conformational flexibility in variable domains and disrupted antigen binding. Conclusions Trp oxidation in CDRs can adversely impact mAbs’ conformation and antigen binding. Trp oxidation should be carefully evaluated as part of critical quality attribute assessments. Oxidation susceptible Trp should be closely monitored during process development for mAbs to establish appropriate analytical control for manufacturing of drug substance and drug product

Quenched QCD at finite density

Simulations of quenched $QCD$ at relatively small but {\it nonzero} chemical potential $\mu$ on $32 \times 16^3$ lattices indicate that the nucleon screening mass decreases linearly as $\mu$ increases predicting a critical chemical potential of one third the nucleon mass, $m_N/3$, by extrapolation. The meson spectrum does not change as $\mu$ increases over the same range, from zero to $m_\pi/2$. Past studies of quenched lattice QCD have suggested that there is phase transition at $\mu = m_\pi/2$. We provide alternative explanations for these results, and find a number of technical reasons why standard lattice simulation techniques suffer from greatly enhanced fluctuations and finite size effects for $\mu$ ranging from $m_\pi/2$ to $m_N/3$. We find evidence for such problems in our simulations, and suggest that they can be surmounted by improved measurement techniques.Comment: 23 pages, Revte

Maintenance of activity and eating change after a clinical trial of tailored newsletters with older rural women.

BACKGROUND: In the Wellness for Women Project, a randomized-by-site 1-year controlled clinical trial, the efficacy of generic newsletters and newsletters tailored on Health Promotion Model behavior-specific cognitions, eating behavior, and activity behavior were compared among 225 women aged 50 to 69 years. OBJECTIVES: The purpose of this study was to compare the maintenance of change in healthy eating and physical activity over the 12 months following the tailored versus generic mailed newsletter intervention. METHODS: Outcomes at 18 and 24 months included behavioral markers and biomarkers of physical activity and eating. Data were analyzed using the multivariate approach to repeated measures analysis of variance and generalized estimating equations (alpha \u3c.05). RESULTS: At 18 months, the tailored group maintained levels of all eating and activity behaviors, whereas the generic group maintained levels of fruit and vegetable servings, a moderate or greater activity, stretching exercise, lower body strength and flexibility but increased saturated fat intake and declined in weekly strength exercise and cardiorespiratory fitness. At 24 months, both groups maintained or returned to 12-month levels of all eating behaviors,moderate or greater activity, stretching exercise, and flexibility but declined in cardiorespiratory fitness; the tailored group maintained levels of strength exercise and lower body strength, whereas the generic group decreased in both. A greater proportion of women who received tailored newsletters continued to achieve most Healthy People 2010 criteria for eating and activity. DISCUSSION: Mailed tailored print newsletters were more efficacious than generic newsletters in facilitating maintenance of change in eating and activity for 6 months postintervention. Both tailored and generic newsletters facilitated the maintenance of change in eating behaviors and in moderate or greater physical activity and stretching exercise, whereas tailored newsletters were more efficacious in maintaining change in strength exercise for 12 months postintervention

Vancomycin-intermediate Staphylococcus aureus in a home health-care patient.

In June 2000, vancomycin-intermediate Staphylococcus aureus (VISA) was isolated from a 27-year-old home health-care patient following a complicated cholecystectomy. Two VISA strains were identified with identical MICs to all antimicrobials tested except oxacillin and with closely related pulsed-field gel electrophoresis types. The patient was treated successfully with antimicrobial therapy, biliary drainage, and reconstruction. Standard precautions in the home health setting appear successful in preventing transmission

Directional Microwave Emission from Femtosecond-laser Illuminated Linear Arrays of Superconducting Rings

We examine the electromagnetic emission from two photo-illuminated linear arrays composed of inductively charged superconducting ring elements. The arrays are illuminated by an ultrafast infrared laser that triggers microwave broadband emission detected in the 1–26 GHz range. Based on constructive interference from the arrays a narrowing of the forward radiation lobe is observed with increasing element count and frequency demonstrating directed GHz emission. Results suggest that higher frequencies and a larger number of elements are achievable leading to a unique pulsed array emitter concept that can span frequencies from the microwave to the terahertz (THz) regime